Just to clarify It's only stable for 2.6 profiles, it's masked for the others (2.4 and "old").
This is to avoid issues with people that are more comfortable with 2.4 kernels, mostly to avoid issues with stability (seems to behave kind of badly on SBUS-based machines in some cases) and upgrade goofs.
I suggest checking the hardware compatibility list if in doubt at http://www.gentoo.org/proj/en/base/sparc/sunhw.xml
On the positive side there will be a 2.6 livecd for the 2006.1 release._________________Gustavo Zacarias
Gentoo/SPARC monkey